Half a dozen egg myths, cracked

Eggs help start your day, define your baking and make a stellar topping for your burger. According to Kelly Trifilo, a registered dietitian affiliated with
Sharp Chula Vista Medical Center, eggs are an egg-ceptional superfood because they raise high-density lipoproteins (HDL) — good cholesterol — and are rich in antioxidants and vitamins.

She cracks a half-dozen common myths about eggs.

You can only keep eggs a week after their "sell by" date.False: "Each carton of eggs graded by the USDA contains a 'sell by' date," says Trifilo. "Refrigerated raw shell eggs will keep for about four to five weeks beyond the 'sell by' date." Hard-boiled eggs should be refrigerated within two hours of cooking and used within one week.

You can tell if an egg has gone bad by testing if it floats in water.True: Trifilo suggests placing the egg in a bowl of cold water. If the egg sinks to the bottom and lies flat, it's fresh. Older eggs will sink at a tilted or upright position. If an egg floats completely, then it is old and should not be used.

"In general, if any egg looks or smells odd, then do not use it," she says.

Eggs need to be refrigerated.It depends: "This may depend on where you are buying and storing eggs," Trifilo says. In the U.S., it's best to store eggs in the fridge. The industrial egg-washing process makes them more susceptible to contamination, so there are regulations in place to protect against harmful pathogens.

"After eggs are refrigerated, they should not be left out more than two hours at a time," she adds.

You shouldn't eat more than one egg per week.False: According to Trifilo, a moderate egg consumption of up to one a day — including egg yolk — can be part of a healthy diet for a healthy individual.

"If you have difficulty controlling your total LDL (bad) cholesterol or have diabetes, then you may want to limit eating egg yolks to only three per week and include meals with egg whites instead," she says.

Trifilo describes how the
body of research suggests that higher consumption of eggs — up to one egg per day — is not associated with increased risk of coronary heart disease or stroke.

"In fact, eggs contain key nutrients for cardiovascular health and are good sources of antioxidants," she says. "The cholesterol response from whole egg consumption will depend on the individual."

Eating raw egg whites is a good source of protein if you are building muscle.False: The CDC advises against eating ordinary raw eggs or undercooked eggs for risk of foodborne illness with salmonella bacteria.

"You can consider looking for labeled pasteurized eggs, which you can use raw," says Trifilo. "Farm-fresh eggs may be eaten raw; however, this depends on the health of the hen. And it's important to find a farmer who you trust."

According to a 2004 study from the
International Journal of Food Sciences and Nutrition, cooked egg whites are more thoroughly digested than raw egg whites because your digestive tract more efficiently dissolves cooked proteins, which are released to the body for energy. Biotin, a B vitamin found in eggs, is better absorbed in cooked eggs.

Consensus: Eating raw eggs won't kill you if you are careful in finding the source, but you may absorb nutrients faster and easier, and decrease your chance of developing foodborne illness, by cooking eggs.